摘要
煤层气井钻井时井径扩径严重程度直接关系到固井对煤储层的污染程度,最终影响煤层气井的产能;不同煤体结构组合决定了井径扩径的钻进主控因素不同。根据焦作矿区恩村井田不同煤体结构的测井响应曲线结合钻井取芯资料,得到不同煤体结构的声波时差值域;统计了各煤层气井不同煤体结构的厚度,划分出各煤层气井不同煤体结构组合及井径扩径严重程度;根据目前的主要钻进参数,系统剖析了不同煤体结构组合条件下的井径扩径的钻进主控因素。分析表明:煤体结构以I类煤为主时,钻井液密度对井径影响最大;煤体结构以II类煤为主时,钻井液密度、天然裂隙发育与最大水平主应力方向的关系对井径影响较大;煤体结构组合中有III类和IV类煤参与时,排量大小对井径的影响最大。
Enlargement rate of well diameter in the drilling process of coal bed methane is be directly related tothe degree of the reservoir pollution ,which will affect the productivity of coal-bed methane wells. At the sametime,the combination of different coal structure impacts the expanding rate of well diameter. Based on the dataof the logging response and drilling in Encun mining field,different fields of sound wave time difference aboutdifferent coal structure are gained. Based on the thickness of different coal structure about coal-bed methane wells,the different combined coal structure and enlargement rate of well diameter are classified. According to the currentmain drilling parameters,the main controlling elements about expanding well diameter in the process of the drillingin different combined coal structure were analyzed. The results show that the density of drilling fluid is the greatestinfluencing element on the enlargement rate of well diameter in I type coal structure;the density of drilling fluid andthe state of the natural fracture affect the enlargement rate of well diameter in II-type coal structure;the displacementis the greatest impacting element on the enlargement rate of well diameter when coal structure contains III type andIV type.
出处
《西南石油大学学报（自然科学版）》
CAS
CSCD
北大核心
2011年第6期135-139,212-213,共5页
Journal of Southwest Petroleum University(Science & Technology Edition)
基金
国家自然科学基金项目(40902044)
中国博士后科学基金项目(20100480848)
河南理工大学博士基金项目(B2009–51)
关键词
煤体结构
井径扩径
钻井液
钻进参数
煤层气
coal structure
hole enlargement
drilling fluid
drilling parameters
coal-bed methane
